(function () {
  "use strict";

  var pseudoClasses = {link: 1, visited: 1, active: 1, hover: 1, focus: 1,
                       "first-letter": 1, "first-line": 1, "first-child": 1,
                       before: 1, after: 1, lang: 1};

  CodeMirror.registerHelper("hint", "css", function(cm) {
    var cur = cm.getCursor(), token = cm.getTokenAt(cur);
    var inner = CodeMirror.innerMode(cm.getMode(), token.state);
    if (inner.mode.name != "css") return;

    var word = token.string, start = token.start, end = token.end;
    if (/[^\w$_-]/.test(word)) {
      word = ""; start = end = cur.ch;
    }

    var spec = CodeMirror.resolveMode("text/css");

    var result = [];
    function add(keywords) {
      for (var name in keywords)
        if (!word || name.lastIndexOf(word, 0) == 0)
          result.push(name);
    }

    var st = token.state.state;
    if (st == "pseudo" || token.type == "variable-3") {
      add(pseudoClasses);
    } else if (st == "block" || st == "maybeprop") {
      add(spec.propertyKeywords);
    } else if (st == "prop" || st == "parens" || st == "at" || st == "params") {
      add(spec.valueKeywords);
      add(spec.colorKeywords);
    } else if (st == "media" || st == "media_parens") {
      add(spec.mediaTypes);
      add(spec.mediaFeatures);
    }

    if (result.length) return {
      list: result,
      from: CodeMirror.Pos(cur.line, start),
      to: CodeMirror.Pos(cur.line, end)
    };
  });
})();
